Day: August 3, 2017

In Phase One, we have a used block and $500–the budget racer has little room for error. The block must be inspected, hot-tanked (cleaned), and Magnafluxed for cracks. Next, Pink recommends pressure-testing the block for leaks by placing the block (filled with air pressure) into a water reservoir. If the block is good–no leaks, no cracks–the next step is to bolt up the main caps (without bearings), measure for diameter size and concentricity, and align. Here comes the kicker! Because we are dealing with a $500 budget, the following scenario may be possible. In the rare occasion that the block in question checks out, align-boring may not be necessary. Remember, we are on a $500 budget. But, if the mains are out-of-round, then align-boring or align-honing will be mandatory. The usual cost for the honing or boring of the mains is $180. Once the mains are align-bored or honed, the centerline of the crankshaft is established.

Next, the block is decked. To deck a block, all four corners of the block are measured to the centerline of the mains (crankshaft) to determine if the block is square (also to set deck height). If the block is off, the head surface is machined until it measures the same, rear to front and side to side (0.001 to maximum tolerance). With the block square, the cylinders can be bored. In our Phase One example, Pink suggested that the block be bored 0.030-inch over. The cylinders are bored or power-honed using a torque plate. To be sure the bore size is correct, Pink suggests that at this time, you ask the machine shop person doing the job about which piston size to use in the engine and piston-to-wall clearances.

With the cylinders bored, we need to stop and do some calculations. We began with $500. The hot tank, pressure testing, and the Magnaflux test cost about $105 to $130. If the mains need to be align-honed (bored), add $180. Decking the block runs about $180. On the high end we have spent about $640; on the low end, $575. If the block did not need to be align-bored (honed), the cost would be $400 to $460. Throw in a few odds and ends (Welsh plug installation, fitting the cam bearing, and so forth), and you have spent the $500 budget plus a few extra bucks–but you have a quality basic block ready for assembly.